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Hba1c Diagnosis Ppt

Glycated Haemoglobin Ppt By Basalingappa Bg

Glycated Haemoglobin Ppt By Basalingappa Bg

1. GLYCATED HEMOGLOBIN(HbA1C) Prepared by: BASALINGAPPA.B.G. 2ND M.Sc. Medical Biochemistry JSS Medical college Mysore 2. TITLE OF HbA1C • Terminology, Definition and Description. • Principle • Methods • Structure • Sample Preparations And Maintenance • Advantages and disadvantages • Normal and abnormal values • Clinical Significance 3. Terminology • Hb: haemoglobin • HbA1: is a series of glycated variants resulting from attachment of various carbohydrates to N terminal valine of Hb. Glycosylation: enzymatic addition of any sugar (glucose)to a protein molecule. • Glycation: when once glucose attached ,it is not removed from the hemoglobin,therefore it remains inside the erythrocyte, so the life span of RBCS(120Days )non enzymatic 4. Some terms • A1c : Glycated haemoglobin together called HbA1 fraction. • IFCC: International Federation of Clinical Chemistry • NGSP: National Glycohaemoglobin Standardisation Programme • DCCT : Diabetes Control and Complications Trial • ADAG : A1c derived average glucose 5. Definition. • Glycated haemoglobin is a form of hemoglobin that is measured primarily to identify the three month average plasma glucose concentration. • The test is limited to a three month average because the lifespan of a red blood cell is three months(120Days). • It is formed in a non-enzymatic glycation pathway by haemoglobin's exposure to plasma glucose. 6. Structure of hemoglobin 7. Principle Glycation of proteins is a frequent occurrence, but in the case of haemoglobin, a non enzymatic reaction occurs between glucose and the N-end of the beta chain. This forms a Schiff base which is itself converted to 1-deoxyfructose. • A Schiff's base a nitrogen analog of an aldehyde or ketone in which the C=0.group is replaced by C=N-R ( Continue reading >>

Hba1c : Glycosylated Hemoglobin

Hba1c : Glycosylated Hemoglobin

1. Glycosylated hemoglobin HbA1c Mathew John MD, DM, DNB Endocrinologist Providence Endocrine & Diabetes Specialty Centre 2. Some terms • A1c : Glycated hemoglobin = glycosylated hemoglobin= glycohemoglobin(US) • IFCC: International Federation of Clinical Chemistry • NGSP: National Glycohemoglobin Standardisation Programme • DCCT : Diabetes Control and Complications Trial • ADAG : A1c derived average glucose 3. Hemoglobin HbA0(α2 ß2) HbA2(α2δ2) HbF(α2γ2) 90 % HbA1 HbA1c Non ezymatically glycosylated form of human hemoglobin, taking place under physiological conditions, at a specific site on the protein 4. Terminology • Hb: hemoglobin • HbA1: is a series of glycated variants resulting from attachment of various carbohydrates to N terminal valine of Hb • Glycation results in increased negative charge and hence runs fast on electrophoresis systems Pickup & Williams , Textbook of Diabetes 5. GHb: glycated hemoglobin 1. HbA1a1: fructose 1,6 diphosphate N terminal valine 2. HbA1a2: glucose 6 phosphate N terminal valine 3. HbA1b: unknown carbohydrate N terminal valine 4. HbA1c: (60-80%): attachment of glucose to N terminal amino acid valine of the beta chain of hemoglobin Total glycated Hb: HbA1c+ sugar Non N terminal sites 6. Amadori rearrangement of glucose molecule. 7. Relationship of HbA1C to Risk of Microvascular Complications Diabetes Control and Complications Trial (DCCT) 15 13 Retinopathy Relative Risk (%) Nephropathy 11 Neuropathy 9 Microalbuminuria 7 5 3 1 6 7 8 9 10 11 12 HbA1C (%) Skyler JS. Endocrinol Metab Clin North Am. 1996;25:243-254. 8. Factors affecting HbA1c Falsely elevated values • HbF or HbG • Uremia ( BUN > 85 mg/dl) • Hypertriglyceridemia( cation exchange +, EP-) • Alcohol • High bilirubin( cation exchange+, HPLC+) • A Continue reading >>

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